import os
import sys
print(sys.path)

# module_a.py  
from module_B.B import some_function_b  
from module_A.sub_module_A.subA import some_function_sub_a
from .a import a

a()

def print_submodule_A():
    some_function_sub_a()

def some_function_a():  
    print("Hello from module_a!")  
  
def main():  
    some_function_a()  
    some_function_b()  
  
if __name__ == "__main__":  
    main()
    

""" 
python module_A/A.py

(base) root@e3f188fe77b5:~/MyCode/imut-ie-2023/run_module_with_m# python module_A/A.py
Traceback (most recent call last):
  File "module_A/A.py", line 2, in <module>
    from module_B.B import some_function_b  
ModuleNotFoundError: No module named 'module_B'
"""

""" 
python -m module_A.A
Hello from module_a!
Hello from module_b!
"""